The present invention relates to technique of distributed information system or distributed information collecting and delivering system such as distributed traffic information collecting and delivering system.
A traffic information system, such as a system of Japan Highway Public Corporation (JH), or Nihon Doro Kodan, relies on traffic information collecting stations built at predetermined locations. The traffic information system of such a centralized type is insufficient in that the number of traffic monitoring positions is limited, and that the method of accessing traffic information is limited.
A Published Japanese Patent Application Publication (Kokai) No. H11(1999)-25130 discloses a traffic information collecting system utilizing a plurality of probe cars functioning as a traffic information monitoring apparatus and supplying traffic information to a server. Traffic information is collected dynamically by a great number of probe cars. This system is a kind of a distributed information system capable of collecting information widely and flexibly without resorting too much to infrastructure.